Switzerland and the United States are "reasonably close" to reaching an agreement to end a long-running dispute over wealthy Americans using secret Swiss accounts to dodge taxes, the Swiss ambassador to the United States told website swissinfo on Tuesday. "We are reasonably close. It's always difficult to predict while negotiations are ongoing, and nothing is agreed until everything is agreed. But I'm confident that a resolution will be reached within a reasonable time frame," Manuel Sager said in an interview published on swissinfo.ch. Eleven Swiss banks, including Credit Suisse, Julius Baer and Basler Kantonalbank, are under formal investigation by the US tax authorities. Media reports have said the two countries are negotiating a tax deal for the whole Swiss banking industry that could involve paying hefty fines and handing over client data in order to escape prosecution in the United States. Sager told swissinfo the US had accepted that Swiss law needed to be adhered to. "Some issues remain open, but I'm confident we will find a resolution," he said. Sager's comments were published as a Swiss court denied a request from a US client of a Swiss bank to stop tax officials from handing over confidential data to the US A court spokeswoman told Reuters the ruling applies to data Credit Suisse handed over to Swiss officials recently. The Swiss secretariat for international financial affairs could not immediately be reached for comment, and a spokesman for Credit Suisse declined comment.